Scientists map local underwater Grand Canyon

Government scientists have released an animated fly-through of the ocean floor off the coast of San Francisco. It's a first-of-its-kind look at the dramatic mountains and ravines that make up what some call an underwater Grand Canyon. We took a look at the latest high tech tool to help preserve critical ocean eco-systems.

When you head out beyond the Golden Gate Bridge, you are heading into the Gulf of the Farallones National Marine Sanctuary, which is 1,300 square miles of underwater habitat protected by law. And we are only just beginning to learn what natural wonders may be here.

"We mapped the sea floor and we found some new geologic structures that we didn't know were out there before," said Maria Brown, a sanctuary superintendent.

Brown is part of a coalition of government agencies that created a 3D animation. They are the most detailed images of the sanctuary geography ever made. They were turned into a video with narration to help the public understand what is here.

Some of the narration said, "The Farallon Islands emerge from the sea 27 miles offshore. They are a bed and breakfast for over a quarter million seabirds."

Just beyond the islands, on the edge of the continental shelf, there is a steep wall of ravines and canyons that plunge more than 6,000 feet deep. This mapping was done with a technique called "multi-beaming".

"You send beams of sound down and it bounces off the sea floor and brings back an image. This allows us to see the relief of the sea floor, to see it go up and down," said Brown.

North and west of the Farallon Islands, the mapping project revealed details of even more canyons and huge shallow banks that create underwater islands. Scientists believe much of this may be critical habitat for a wide variety of different creatures.

One area scientists looked at is few miles south of Cordell Bank. They visited and took video of the area two years ago. Cordell Bank is full of spectacular life and the newly-discovered areas hold the promise of similar diversity, huge schools of fish, sea urchins, sponges and deep sea corals.

"Coral reefs provide habitat for commercially valuable fish so it's really important we protect these areas. If we have a strong, healthy ocean environment, that's going to support ocean industries such as commercial fishing," said Maria.

Exploring the ocean is challenging -- conditions can be harsh and many of the of habitats are too deep for divers. Now that scientists have a detailed map to show them where to look, the next step will be an expedition this fall with a remotely operated vehicle to take pictures.

"In order for us to adequately protect the sanctuary and marine environment, we need to know what's out there," said Brown.